Is leaf dry matter content a better predictor of soil fertility than specific leaf area?

BACKGROUND AND AIMS: Specific leaf area (SLA), a key element of the 'worldwide leaf economics spectrum', is the preferred 'soft' plant trait for assessing soil fertility. SLA is a function of leaf dry matter content (LDMC) and leaf thickness (LT). The first, LDMC, defines leaf construction costs and can be used instead of SLA. However, LT identifies shade at its lowest extreme and succulence at its highest, and is not related to soil fertility. Why then is SLA more frequently used as a predictor of soil fertility than LDMC? METHODS: SLA, LDMC and LT were measured and leaf density (LD) estimated for almost 2000 species, and the capacity of LD to predict LDMC was examined, as was the relative contribution of LDMC and LT to the expression of SLA. Subsequently, the relationships between SLA, LDMC and LT with respect to soil fertility and shade were described. KEY RESULTS: Although LD is strongly related to LDMC, and LDMC and LT each contribute equally to the expression of SLA, the exact relationships differ between ecological groupings. LDMC predicts leaf nitrogen content and soil fertility but, because LT primarily varies with light intensity, SLA increases in response to both increased shade and increased fertility. CONCLUSIONS: Gradients of soil fertility are frequently also gradients of biomass accumulation with reduced irradiance lower in the canopy. Therefore, SLA, which includes both fertility and shade components, may often discriminate better between communities or treatments than LDMC. However, LDMC should always be the preferred trait for assessing gradients of soil fertility uncoupled from shade. Nevertheless, because leaves multitask, individual leaf traits do not necessarily exhibit exact functional equivalence between species. In consequence, rather than using a single stand-alone predictor, multivariate analyses using several leaf traits is recommended.

Coriocarcinoma cervical metastásico en mujer de 45 años con antecedente de HSIL / Metastatic choriocarcinoma in a 45-year-old woman with a previous high-grade squamous intraepithelial lesion

El coriocarcinoma es una neoplasia epitelial rara, perteneciente al grupo de las enfermedades trofoblásticas gestacionales. Se caracteriza por la presencia de células del sincitotrofoblasto, citotrofoblasto y trofoblasto intermedio, que pueden presentar invasión tisular y vascular. Resumen Mujer de 45 años, última gestación 10 años atrás. Recibe tratamiento de lesión escamosa intraepitelial de alto grado (HSIL). Tras conización, presenta sangrados irregulares. Descartada la posibilidad de enfermedad cervical residual o patología de origen endometrial, nos orientamos hacia el diagnóstico de coriocarcinoma cuando la paciente presenta hemoptisis por metástasis pulmonares. Se realiza revisión de los criterios diagnósticos, manifestaciones clínicas y pronóstico (AU)

Choriocarcinoma is a rare epithelioid neoplasm belonging to the group of gestational trophoblastic disease. The histologic feature is syncytiotrophoblastic, cytotrophoblastic and intermediate trophoblastic cells which can permeate among the myometrial fibers and vessels. AbstractWe report a case of choriocarcinoma diagnosed in a 45-year-old woman 10 years after her last pregnancy. She was treated for a high-grade squamous intraepithelial lesion (HSIL). After surgical treatment, she showed irregular vaginal bleeding. Once residual cervical disease and endometrial disease had been excluded, we suspected metastatic gestational trophoblastic disease when the patient showed hemoptysis due to pulmonary metastasis. We review the diagnostic criteria, clinical expression and prognosis of this entity (AU)

[Induced drug prescription in oncology patients]. / Estudio de la prescripción farmacológica inducida en pacientes oncológicos.

AIM: To study drug prescription generated by cancer patients treated at the Emergency Service (ES) of the Instituto Valenciano de Oncología (IVO) in their Primary Health Care Centre (PHCC). MATERIAL AND METHODS: A descriptive prospective study has been carried out with patients treated and discharged from the ES of the IVO in November (n=207) and December (n=239) of 2001. 446 patients were treated and discharged; one out of five patients was contacted by telephone 48 hours after discharge to confirm drug prescriptions from the ES. In November, drug prescription was based on brand-name products, while, in December, generic drugs were prescribed. All patients were discharged with a detailed report that included: patient's medical records, consultation reason, physical exploration performed, diagnostic test results, discharge diagnosis and prescribed treatment. When a brand-name drug was prescribed, the majority of patients received the same product at the PHCC (92.5%), while the rest of them received the same active drug with a different brand name. When a generic drug was prescribed, patients received a prescription for the same active substance at the PHCC in 98% of cases (46% generic drug and 54% brand-name). As to length of treatment, 96% were short treatments (less than 2 weeks), while the rest of them were on-going. 80% needed one prescription; 15%, two, and 5% three or more prescriptions. In terms of therapeutic groups, the most commonly prescribed drugs were anti-infectious, analgesics, digestive-metabolism, respiratory, cardiovascular, neurological and miscellaneous. CONCLUSIONS: 1. There is a high level of induced drug prescription at PHCC in cancer patients, since primary care physicians usually maintain active substances prescribed by the ES of IVO, with few variations. 2. Promoting a good relationship between Hospital Care and Primary Health Care Centres helps control and reduce pharmaceutical costs. 3. A high correlation can be found between most frequently prescribed drugs in oncological patients and non-oncological patients seen in Primary Health Care.

Síndrome de transfusión feto-fetal / Twin-twin transfusion syndrome

El síndrome de transfusión feto-fetal (STFF) es una complicación que se presenta en un 10-15 per cent de las gestaciones gemelares monocoriales biamnióticas. Es una afección exclusiva de este tipo de gemelaridad y se caracteriza por la presencia de anastomosis arteriovenosas cuyo flujo unidireccional no está equilibrado por otras conexiones vasculares y, por consiguiente, se produce la secuencia oligoamnios-hidramnios. La afección fetal es debida a una hipovolemia del gemelo donante y a una hipervolemia del gemelo receptor. Presentamos nuestra experiencia en este tipo de enfermedad. En los casos presentados, diagnosticados al final del segundo trimestre, se llevaron a cabo como medida terapéutica amniodrenajes seriados, los cuales permitieron prolongar la gestación para la maduración pulmonar fetal, aunque no solucionaron el STFF. Realizamos, asimismo, una revisión en cuanto a las diferentes opciones de tratamiento actual que van desde la conducta expectante, con una mortalidad cercana al 100 per cent, hasta los tratamientos etiológicos basados en la ablación selectiva con láser de los vasos comunicantes con una supervivencia de al menos un gemelo del 70 per cent, con una tasa de handicap neurológico menor al 5 per cent. (AU)

Susceptibilidad genética del gen del receptor de la glucoproteína IIb/IIIa de la membrana plaquetaria y del inhibidor del activador del plasminógeno (PAI-1) en el contexto de la diabetes gestacional / Genetic susceptibility to Glycoprotein IIb/IIIa platelet receptor genes, and Plasminogen Activator Inhibitor (PAI-I) in the context of gestational diabetes

El objetivo de este trabajo es determinar la susceptibilidad genética ejercida por el PAI-1 y el receptor GP IIb/IIIa de las plaquetas en la patogenia de la activación del sistema de la coagulación en la diabetes gestacional (DG). Se seleccionaron muestras biológicas de 151 gestantes; n = 74 con DG y n = 77 control. Se analizaron los polimorfismos genéticos para el gen de la GP IIb IIIa y el PAI-1 y el estudio de los parámetros de la coagulación TF, proteína S, proteína C, antitrombina III, factor II, fibrinógeno, TPTA Y TP. La presencia del alelo 4G se asoció con un mayor riesgo de presentar complicaciones entre las DG (37,2% frente a 53,1% para la ausencia y presencia de complicaciones, respectivamente) y en el grupo de DG se hallaron diferencias significativas en los valores de fibrinógeno para el genotipo A1/A1 y el haplotipo A1A1-5G5G (p < 0,05). La asociación de determinadas combinaciones alelicogenotípicas de los marcadores analizados en el grupo de pacientes con DG hace pensar en la existencia de una participación genética en la variabilidad de determinados parámetros de la hemostasia en esta subpoblación (AU)

Reduction of tris(benzene-1,2-dithiolate)molybdenum(VI) by hydroxide ions in dry tetrahydrofuran solution.

Tris(benzene-1,2-dithiolate)molybdenum(VI) reacts rapidly and quantitatively with tetrabutylammonium hydroxide to yield the corresponding Mo(V) and Mo(IV) complexes and hydrogen peroxide; the reaction has been executed in dry tetrahydrofuran where the reaction rate shows a fair dependence on complex and OH- concentrations.

La Difusión en la reacción Antígeno-Anticuerpo / Diffusion in the antigen antibody reaction

En trabajos realizados anteriormente se han observado algunos indicios sobre la importancia de la difusión molecular en la reacción antígeno–anticuerpo. Para el tratamiento de los resultados se utilizaron exclusivamente ajustes polinómicos, los cuales tienen la ventaja de su sencillez y generalidad, pero son poco informativos en cuanto a las características inherentes al proceso. En el presente trabajo se partió de los resultados obtenidos en varias series de experiencias tendentes al estudio de la cinética de distintas reacciones antígeno anticuerpo. En la mayor parte de ellas, se utilizaron antígenos marcados con I125 y en algunos casos, anticuerpos con este mismo radionúclido. En todos los casos se siguió el curso de la reacción midiendo la radiactividad del inmunocomplejo Ag-Ac formado a diferentes tiempos, directamente proporcional a su concentración, porque los datos de partida son siempre tablas: Actividad, en cuentas por minuto (CPM), representada por A, frente al tiempo (t) en minutos. Los resultados obtenidos para un total de dieciséis reacciones se analizan utilizando exlusivamente el método integral mediante los modelos de Stenberg y Karlsson, cada uno de los cuales suministra una ecuación de velocidad integrada que ha sido adaptada para aplicarla a los valores disponibles. Se observa control por difusión en un elevado tanto por ciento de los casos estudiados. (AU)

Determination of the anti-platelet-activating factor BN-50727 and metabolites in human urine by high-performance liquid chromatography using solid-phase extraction.

A sensitive and selective HPLC solid-phase extraction procedure was developed for the determination of platelet-activating factor antagonist BN-50727 and its metabolites in human urine. The procedure consisted in a double solid-phase extraction of the urine samples on cyanopropyl and silica cartridges, followed by an automated solid-phase extraction of the drug and metabolites on CBA cartridges and posterior elution on-line to the chromatographic system for its separation. The method allowed quantitation in the concentration range 10-2400 ng/ml urine for both BN-50727 and the main metabolite, the O-demethylated BN-50727 product. The limit of quantitation for both compounds was 10 ng/ml. The inter-assay precision of the method, expressed as relative standard deviation, ranged from 1.9 to 4.5% for BN-50727 and from 2.5 to 9.0% for the metabolite. The accuracy, expressed as relative error, ranged from -2.4 to 4.2% and from 0.2 to 6.2%, respectively. This paper describes the validation of the analytical methodology for the determination of BN-50727 in human urine and also for its metabolites. The method has been used to follow the time course of BN-50727 and its metabolites in human urine after single-dose administration.

Determination of the anti-platelet-activating factor BN-50727 and its metabolites in human plasma by high-performance liquid chromatography-solid-phase extraction.

A sensitive and selective HPLC-solid-phase extraction procedure was developed for the determination of platelet-activating factor antagonist BN-50727 and its metabolites in human plasma. The procedure consisted of an automated solid-phase extraction of the drug and metabolites on disposable propylcarboxylic acid cartridges, followed by on-line chromatographic separation. The method was linear from 3.75 to 2400 ng/ml and the limit of quantitation for BN-50727 in plasma samples was 3.75 ng/ml. The within-run precision of the method, expressed as relative standard deviation, ranged from 2.1 to 8.1%. The accuracy, expressed as relative error, ranged from -3.5 to 4.0%. For the main metabolite, the O-demethylated BN-50727 product, the method was linear from 7.5 to 2400 ng/ml and the limit of quantitation in plasma was 7.5 ng/ml. The within-run precision ranged from 2.1 to 11.0% and the accuracy from -5.3 to 1.1%. This paper describes the validation of the analytical methodology for the determination of BN-50727 in human plasma and also of its metabolites. The method has been used to follow the time course of BN-50727 and its metabolites in human plasma after administration of single and multiple doses.

Prenatal diagnosis of exencephaly.

This paper presents a sonographic diagnosis of exencephaly made during the last trimester of gestation. The sonogram showed the absence of bones in the cranial vault together with the presence of a disorganized cerebral mass, with loss of its normal anatomy. Post-partum examination of the newborn confirmed the findings of the sonogram. We briefly review the characteristics of exencephaly, its aetiology, and its relationship to anencephaly.